The present invention generally relates to reduction of the power consumed by a storage system.
Advancements in information technology in recent years have been accompanied by a dramatic increase in the volumes of data handled by business computer systems. The resultant increase in capacity and performance of the storage systems in which the data handled by a computer system is stored has led to increased storage system power consumption. Accordingly, reduction of the power consumed by a storage system is desired. Examples of technologies related to reduction of the power consumed by a storage system are disclosed in Japanese Unexamined Patent Application No. 2000-293314 and Japanese Unexamined Patent Application No. 2003-296153. According to the technology disclosed in Japanese Unexamined Patent Application No. 2000-293314, an unaccessed magnetic disk device is migrated to an energy-saving mode after a predetermined time has elapsed. According to the technology disclosed in Japanese Unexamined Patent Application No. 2003-296153, at times of low load, a data storage position control device for a plurality of storage units redirects processing to another processing device, and migrates the CPU to a power-saving mode.
Each of the aforementioned magnetic disk device and CPU are devices that participate in the processing of I/O commands received by a storage system (hereinafter I/O process-participating devices) from a host device. There is possibility that storage system performance will deteriorate as a result of an I/O process-participating device being migrated to a power-saving state.